1. Field of the Invention
The present invention relates to the application of a liquid to a web (which is a long flexible belt-like uncoated or coated material such as a plastic film, paper and a metal sheet) with the use of a web vibration absorber so as to assure the flatness of the web in manufacturing the web.
2. Background of the Invention
In a conventional method of absorbing the vibration of an uncoated or coated web such as a plastic film, paper and a metal sheet in manufacturing the web, a roller, a drum, a suction table or the like has been used for the absorption of the vibration.
However, when a liquid is applied to both sides of a web and a drier is used to dry the applied liquid without coming into contact with either side of the web, none of the above described mechanical contact absorbers can be used to absorb the vibration of the web caused by an ejected gas in the drier and a web mover in order to prevent the vibration from adversely affecting the application of the liquid. Alternatively, a method can be used, such as that disclosed in the Japanese Patent Application (OPI) No. 109162/83, where (the term "OPI" as used herein means an "unexamined published application") in which the liquid is applied while pushing an extrusive application head which is little adversely affected by the vibration is adopted. However, even in this case, the vibration causes the thickness of the film of the applied liquid to be made non-uniform in the direction of the movement of the web. For these reasons, it has been difficult to put into practical use a process of simultaneously performing both the application of the liquid to both the sides of the web and the drying of the applied liquid thereon.